refactor(release): 改为 Agent 双阶段人工发布

删除 Gitea Actions、Tag/Main 自动流水线和旧 Runner 配置，取消 Git 操作与发布授权的绑定。\n\n新增本地镜像发布、固定生产部署助手、digest manifest、迁移安全检查、simulation 冒烟及显式回滚流程。\n\n验证：pnpm lint、pnpm test、pnpm build、Go 全量测试、ShellCheck、Compose 配置、人工发布测试和 linux/amd64 完整栈冒烟。

package.json

@@ -12,8 +12,9 @@
     "migrate": "nx run api:migrate",
     "openapi": "nx run api:openapi",
     "docker:build": "docker compose -f docker-compose.yml build --pull api web",
-    "docker:push": "scripts/deploy-compose.sh push-only",
-    "docker:deploy": "pnpm docker:build && pnpm docker:push"
+    "release:publish": "scripts/publish-release-images.sh --components auto",
+    "release:deploy": "scripts/deploy-production-release.sh",
+    "test:release": "tests/release/manual-release-test.sh && tests/ci/migrations-test.sh"
   },
   "devDependencies": {
     "@nx/vite": "^21.0.0",